BTC Cash-and-Carry Quarterly Basis Convergence, Market-Neutral (Long BTCUSDT.BINANCE_SPOT + Short the Nearest-Expiry BTC USD-M DATED QUARTERLY Future, Held to Settlement to Capture the DETERMINISTICALLY-CONVERGENT Contango Basis — NOT Perp Funding, Rolled at Expiry, 2-Parameter)

A MARKET-NEUTRAL cash-and-carry on BTC that harvests the QUARTERLY-FUTURE basis, which is categorically different from every funding/perp carry that has died in this factory. The dead carries (BTC/AVAX/BNB/ETH spot-perp, all fee_edge) relied on PERP funding — a thin (~1bp/8h median), non-convergent cash flow that never exceeds the round-trip cost. A DATED quarterly future is different in kind: it must converge to spot AT SETTLEMENT (deterministic, contractual), and BTC quarterlies trade in persistent CONTANGO of typically 5-15% ANNUALIZED (~125-375 bps over a ~90-day hold) — an order of magnitude above the ~0.30% two-leg round-trip, and it clears L1's >20bps/cycle bar by a wide margin because the basis is a term premium, not a funding tick. Structure: LONG BTC spot + SHORT the nearest-listed BTC USD-M quarterly at equal notional (delta-neutral), hold to (or near) settlement so convergence is captured with essentially ONE entry round-trip and no exit churn (the legs converge on their own), then roll into the next quarterly. This escapes ALL the recurring killers: FEE_EDGE — basis >> fees, and holding to settlement means ~2 fills per quarter, near-zero turnover; MULTI-REGIME — the basis exists and converges in bull AND bear (not a single-regime beta artifact like the long-only timers); OVERFIT — 2 parameters (entry-basis threshold, roll timing), no selection surface; and it is not the abandoned reversion class. It fills the under-represented cross-venue (7.3%) and market-neutral direction buckets. CRITICAL DATA DEPENDENCY (flagged so it fails fast rather than looping): this requires historical kline coverage of the DATED BTC USD-M quarterly contracts in the catalog — the developer must verify quarterly-future history is available for the backtest window BEFORE coding; if only perp/spot bars exist, abandon immediately (do not substitute the perp, which would revert this to the dead funding carry).